Hosted providers¶

MotherDuck's prompt_jev SQL function answers the same three primitives (choice, score, yes/no) and returns a choice, a full probability distribution and a confidence (DESIGN D16). mesa-anyjev asks it the identical questions: the frozen question text is the instruction, the frozen option list is the choice := [...] constant, and the State: text is the same rendering AnyJev prefills, so a hosted answer and a local answer to one state share the state_sha256. The SQL literal for every question is pinned in questions.lock.json (hosted_sql) beside its key, without entering the lock sha.

What a hosted record is¶

provider='motherduck', method='hosted:prompt_jev', level='none' (no AnyJev level exists for it), calibration='typesafe' with the distribution re-ordered into the frozen option order. Three things never become a probability: a value the frozen options do not contain, a distribution that does not sum to one, and a NULL answer (MotherDuck returns NULL for a failed request and the query continues). Those records abstain with calibration='none' and the reason in diagnostics; a NULL is recorded as decider_unavailable. The observed return shape (STRUCT(choice, probabilities[], confidence) for choice, a DOUBLE for yes/no, a weighted position for score) is pinned in the parser and in the doctor, so a change in the preview fails loudly.

Scoring stored states¶

export MOTHERDUCK_TOKEN=...      # read by the DuckDB extension; never stored in config
MESA_ANYJEV_POLICY__HOSTED_PROVIDERS=allowlist \
  uv run mesa-anyjev hosted score --question term.fits --source labels --dry-run
MESA_ANYJEV_POLICY__HOSTED_PROVIDERS=allowlist \
  uv run mesa-anyjev hosted score --question term.fits,column.aspect --source labels

--dry-run prints the rows, requests (32 rows per request) and approximate input tokens without sending anything. A real run records a normal sidecar run with backend_kind='motherduck', data_left_host=true and the egress region, one decision row per state, and, when the states carry labels, a results file of its own (bench/results/<date>/motherduck__prompt_jev.motherduck.json), never mixed with gateway or local rows. --source run --run-id <id> re-scores the decisions of a local run so the two providers can be compared state by state. Re-scoring effective AVUs straight from the DuckLake history waits for states that carry the dataset card.

Data residency¶

Because the state leaves the host, hosted providers are off by default (policy.hosted_providers: off) and the CLI, the service and the doctor refuse them. With allowlist, a local source (labels, fixtures, a sidecar run on this host) is allowed when hosted_allow_local_sources is true, and a project only when its root is listed in hosted_allow_project_roots or carries mesa.hosted_inference=allow. The prod profile allows auto for AnyJev-calibrated records only, so a hosted decision may be proposed but never auto-writes until a bench row in its own results file cites its coverage at 5% risk. mesa-anyjev doctor adds the MotherDuck checks (extension, token present by name only, md: attach, a two-option fixture, the pinned shape) whenever the policy is not off.